(1) Field of the Invention
The present invention relates to high frequency communications and is directed more particularly to a design for a portable wideband antenna-radiated signal generator.
(2) Description of the Prior Art
Often, personnel such as EM (electromagnetic) and communication engineers/technicians require a test signal to be generated in order to perform continuity tests of an RF (radio frequency) transmission path through an antenna that is coupled to a receiver. To perform such tests, the personnel are often required to carry relatively expensive, sensitive, large, and heavy test equipment that inconveniently rely upon line power. The testing is especially even more problematic when operating on vessel platforms such as submarines where personnel are required to carry the test equipment through the submarine sail to conduct the test. Commonly encountered difficulties encountered while performing the tests include requirements that personnel must carry heavy and bulky test equipment, that expensive equipment be available, procedures that entail long test setup and breakdown times, and the need for ship power to power the test equipment.
In the prior art, wideband signal generation is addressed:
In Telewski (U.S. Pat. No. 3,777,271), a step recovery diode is driven by two or more frequencies to form a harmonic generator.
In McEwan (U.S. Pat. No. 5,274,271), an output pulse generator for wideband applications is disclosed.
In Nelson et al. (U.S. Pat. No. 5,369,373) the step recovery diode 14 is disclosed that is driven by a sine-wave oscillator 12. In response, a wideband series of harmonics of the fundamental frequency is produced by frequency oscillator 12. The output of the step recovery diode 14 is supplied to one or more bandpass filters or lowpass filters which provide selection windows so that only a specified number of harmonic lines are passed within a selection window.
In Nellson, (U.S. Pat. No. 5,793,309) a short-range electromagnetic transceiver is disclosed in which an oscillator 14 excites a step recovery diode 12. The output of step recovery diode 12 is provided to a filter 24 that acts as a harmonic filter and selects the particular frequency of transmission. The output of filter 24 is gated to produce a short RF pulse which is a harmonic of the input excitation signal and is in the GHz range. The short RF pulse is propagated normal to the circuit and through space until it is dissipated or reflected from a target back into the antenna 20.
As indicated in the references above, a need still exists for an efficient portable wideband antenna-radiated signal generator system design. An additional need exists for an energy efficient method for producing a wideband antenna-radiated signal.